The invention relates to an optical recording element comprising a transparent supporting plate, a dye-containing recording layer and a first reflective layer which is applied to a recording layer, said element having a ROM (read only memory) region containing information which can be read optically and a RC (recording) region in which information can be recorded and read optically.
Such an optical recording element is known from the published Europeant Patent Application No. 0353391, to which U.S. Pat. Nos. 4,940,618 and 4,920,388 correspond.
According to exemplary embodiment 1 of the above-mentioned European Patent Application, a layer of an organic cyanine dye is used as the recording layer. Said layer is manufactured by dissolving the dye in an organic solvent. The solution obtained is then provided on the part of the substrate which corresponds to the RC region by means of a customary spin-coating process. During spin-coating, the solvent evaporates and a solid dye layer is obtained. Subsequently, the entire surface of the substrate and the dye layer is provided with an Au-reflective layer which in turn is covered with a protective layer of a UV-cured resin.
Applicants have established that the use of a dye-containing recording layer leads to a low light reflection (&lt;30%) in the boundary region between the ROM region and the RC region. In the ROM and RC regions themselves a light reflection of 70% or more is attained. When using the optical recording element, the information present in the ROM region is scanned by a focused laser light beam. Said laser light beam crosses the boundary line between the ROM region and the RC region and is then directed via guide tracks to a position in the RC region. The laser light energy is increased and an information bit is recorded. This example serves to illustrate that the boundary line between the ROM and RC regions is cross very frequently. It has been found that as a result of the very low reflection in the boundary region between the ROM and RC regions the focusing and control of the laser light beam are no longer accurate and, hence, that a correct recording and reading process is no longer possible.